<template>
    <!-- 主页组件 -->
  <el-container class="home-container">
    <!-- 1.头部区域 -->
    <el-header>
      <div class="logo">
        <img src="../assets/logo.png" alt="">
        <span>后台管理系统</span>
      </div>
      <el-button type="info" @click="logout">退出</el-button>
    </el-header>
    <!-- 2.页面主体区域 -->
    <el-container>
      <!-- 2.1侧边栏 -->
      <el-aside :width="isCollapse ? '64px' : '200px'">
        <!-- 点击隐藏侧边栏 -->
        <div class="toggle-button" @click="toggleCollapse">|||</div>
        <!-- 侧边栏菜单区域 -->
        <el-menu background-color="#333744" text-color="#fff" active-text-color="#409eff" unique-opened :collapse="isCollapse" :collapse-transition="false" router :default-active="activePath">
          <!-- 一级菜单 -->
          <el-submenu :index="item.id + ''"  v-for="item in menuList" :key="item.id">
            <!-- 一级菜单模板区域 -->
            <template slot="title">
              <!-- 图标 -->
              <i :class="iconObj[item.id]"></i>
              <!-- 文本 -->
              <span class="menu-text">{{item.authName}}</span>
            </template>

            <!-- 一级菜单的二级菜单 -->
            <el-menu-item :index="'/' + subItem.path + ''" v-for="subItem in item.children" :key="subItem.id" @click="saveNavState('/' + subItem.path + '')">
                <template slot="title">
                <!-- 图标 -->
                <i class="el-icon-menu"></i>
                <!-- 文本 -->
                <span>{{subItem.authName}}</span>
            </template>
            </el-menu-item>
          </el-submenu>
        </el-menu>
      </el-aside>
      <!-- 2.2右侧内容主体 -->
      <el-main>
        <!-- 路由占位符 -->
        <router-view></router-view>
      </el-main>
    </el-container>
  </el-container>
</template>

<script>
export default {
  data () {
    return {
      // 左侧菜单数据
      menuList: [],
      // 左侧一级菜单图标
      iconObj: {
        125: 'el-icon-s-custom',
        103: 'el-icon-unlock',
        101: 'el-icon-s-shop',
        102: 'el-icon-s-order',
        145: 'el-icon-s-data'
      },
      // 是否折叠左侧菜单栏
      isCollapse: false,
      // 被激活的二级菜单链接地址
      activePath: ''
    }
  },
  created () {
    // 生命周期函数，页面一加载就执行获取左侧菜单列表的方法
    this.getMenuList()
    this.activePath = window.sessionStorage.getItem('activePath')
  },
  methods: {
    // 退出登录方法，清除token，跳转到登录界面
    logout () {
      window.sessionStorage.clear()
      this.$router.push('/loginUser')
    },
    // 获取所有左侧菜单的方法
    async getMenuList () {
      const { data: res } = await this.$http.get('menus')
      // console.log(res)
      if (res.meta.status !== 200) return this.$message.error(res.meta.msg)
      this.menuList = res.data
    },
    // 点击按钮切换菜单的折叠与展开方法
    toggleCollapse () {
      this.isCollapse = !this.isCollapse
    },
    // 保存二级菜单链接的激活状态
    saveNavState (activePath) {
      window.sessionStorage.setItem('activePath', activePath)
      this.activePath = activePath
    }
  }

}
</script>

<style scoped>
.home-container {
  height: 100%;
}
.el-header {
  background-color: #373d41;
  display: flex;
  justify-content: space-between;
  padding-left: 0;
  align-items: center;
  color: #fff;
  font-size: 20px;
}
.logo {
  display: flex;
  align-items: center;
}
.logo > img {
  width: 60px;
}
.logo > span {
  margin-left: 15px;
}
.el-aside {
  background-color: #333744;
}
.el-main {
  background-color: #eaedf1;
}
.menu-text {
  margin-left: 10px;
}
.el-menu {
  border-right: 0;
}
.toggle-button {
  background-color: #4a5064;
  font-size: 10px;
  line-height: 24px;
  text-align: center;
  letter-spacing: 0.2em;
  cursor: pointer;
}
</style>
